The drug trade began in Mexico, where methamphetamine can be made more easily than in the U.S., said Jane Duke, federal prosecutor for the eastern district of Arkansas. Many U.S. states, including Arkansas, regulate the sale of ephedrine and pseudoephedrine, ingredients found in cold medicine that can be used in bulk to make meth.

A three-year investigation _ dubbed "Tienda Hielo" or "Ice Store" _ into the drug ring has led to about 65 arrests and the seizure of more than 100 pounds of meth, which would have a street value of about $11 million, Duke said. Local, state and federal authorities announced the drug bust Thursday.

According to Duke, the drug was manufactured in Mexico, then brought over the border into San Diego. From there, couriers would transport the drugs throughout the country, sometimes carried on passenger buses cross-country, other times in so-called "clone trucks," which are made to look like commercial trucks delivering soft drinks or food, said Lt. Keith Eremea of the Arkansas State Police.

Eremea said state troopers are trained to look "for things that just don't look right." According to Eremea, drugs are sometimes hidden in complicated electronic traps that can only be accessed through certain settings on the car. For example, a hiding place would open up only if the cruise control was on and the air conditioner was set to a certain level.

William Bryant, assistant special agent in charge for Little Rock's Drug Enforcement Administration office, said federal officials would sometimes search a vehicle, not find any drugs and then call in state police, who could find the methamphetamine.

In Arkansas, the traffickers mainly stuck to Interstates 30 and 40 and Batesville, which served as a hub in this state, the authorities said.

Duke said the meth had a purity level greater than 80 percent and was shipped from regional hubs in Dallas, Phoenix, and San Diego to the Batesville area before distribution to cities that included Memphis, Tenn.; Kansas City, Mo.; Des Moines, and Indianapolis.

Prosecutors said there were three ringleaders of the operation _ husband and wife Octavio and Argelia Herrera of California, along with Felipe Valdez. The Herreras have been indicted and arrested, but Valdez remains a fugitive, Bryant said.

Argelia Herrera, of Chula Vista, Calif., has pleaded guilty to drug charges and is awaiting sentencing. Others involved in the smuggling ring face up to life in prison.